arch/mips/lantiq/xway/dcdc.c

   1 /*
   2  *  This program is free software; you can redistribute it and/or modify it
   3  *  under the terms of the GNU General Public License version 2 as published
   4  *  by the Free Software Foundation.
   5  *
   6  *  Copyright (C) 2012 John Crispin <blogic@openwrt.org>
   7  *  Copyright (C) 2010 Sameer Ahmad, Lantiq GmbH
   8  */
   9
  10 #include <linux/ioport.h>
  11 #include <linux/of_platform.h>
  12
  13 #include <lantiq_soc.h>
  14
  15 /* Bias and regulator Setup Register */
  16 #define DCDC_BIAS_VREG0 0xa
  17 /* Bias and regulator Setup Register */
  18 #define DCDC_BIAS_VREG1 0xb
  19
  20 #define dcdc_w8(x, y)   ltq_w8((x), dcdc_membase + (y))
  21 #define dcdc_r8(x)      ltq_r8(dcdc_membase + (x))
  22
  23 static void __iomem *dcdc_membase;
  24
  25 static int dcdc_probe(struct platform_device *pdev)
  26 {
  27         struct resource *res;
  28
  29         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  30         dcdc_membase = devm_ioremap_resource(&pdev->dev, res);
  31         if (IS_ERR(dcdc_membase))
  32                 return PTR_ERR(dcdc_membase);
  33
  34         dev_info(&pdev->dev, "Core Voltage : %d mV\n",
  35                 dcdc_r8(DCDC_BIAS_VREG1) * 8);
  36
  37         return 0;
  38 }
  39
  40 static const struct of_device_id dcdc_match[] = {
  41         { .compatible = "lantiq,dcdc-xrx200" },
  42         {},
  43 };
  44
  45 static struct platform_driver dcdc_driver = {
  46         .probe = dcdc_probe,
  47         .driver = {
  48                 .name = "dcdc-xrx200",
  49                 .owner = THIS_MODULE,
  50                 .of_match_table = dcdc_match,
  51         },
  52 };
  53
  54 int __init dcdc_init(void)
  55 {
  56         int ret = platform_driver_register(&dcdc_driver);
  57
  58         if (ret)
  59                 pr_info("dcdc: Error registering platform driver\n");
  60         return ret;
  61 }
  62
  63 arch_initcall(dcdc_init);